Actuator device for well tool



Jan. 17,1967

ACTUATOR DEVICE FOR WELL TOOL Filed Aug. 19. 1964 M. B. CONRAD 3,298,437

2 Sheets-Sheet l F25. Jfi.

714,457 a. Cd/V240 INVENTOR.

I BY

Jan. 17, 1967 M. B- CONRAD 3,

I ACTUATOR DEVICE FOR WELL TOOL Filed Aug. 19, 1964 Z-Sheets-Sheet 2 Y 2 6122;. 2 2%. 2;: F16. Z6,

MAZf/A/ 5 66/14649 INVENTOR.

United States Patent 3,298,437 ACTUATOR DEVICE FOR WELL TOOL Martin B. Conrad, Downey, Calif. (R0. Box 568, Carpinteria, Calif. 93013) Filed Aug. 19, 1964, Ser. No. 390,687 9 Claims. (Cl. 166-63) This invention relates to an actuator for a well tool and is particularly directed to a setting tool for a bridge plug.

The objects of the present invention are to provide a setting tool for a bridge plug in a well, the setting tool being energized by high-pressure gas obtained, for example, by ignition of a powder charge within the setting tool. Another object is to provide a device of this type of short over-all length, and yet having adequate stroke to actuate well tools of various sizes and types. Another object is to provide a device of this type which is hydrostatically balanced so that it operates equally well in a dry hole or submerged in liquid to any depth in the well. Another object is to provide a device of this type in which recoil after firing is minimized or substantially eliminated. A related object is to provide a device of the type described which is economical to manufacture, having relatively few parts and reliable in operation.

Other and more detailed objects and advantages will appear hereinafter.

In the drawings:

FIGURE 1 shows a preferred embodiment of this invention in longitudinal sectional elevation, FIGURE 1b comprising a continuation of the lower end of FIGURE 1a, and FIGURE 10 comprising a continuation of the lower end of FIGURE 112. FIGURE 1 shows the parts of the actuator for setting tool and the parts of the bridge plug in initial position prior to firing.

FIGURE 2 is a view similar to FIGURE 1, showing the parts in position after firing and showing the bridge plug set within the casing. FIGURE 2b is a continuation of the lower end of FIGURE 2a, and FIGURE 20 is a continuation of the lower end of FIGURE 2b.

Referring to the drawings, the actuator device generally designated 10 comprises a setting tool adapted to be lowered into a well casing 11 on a wire line 12. A bridge plug assembly 13 of conventional design is attached to the lower end of the actuator 10 by means of the frangible connector 14 and spacer 15. In the general plan of operation, the setting tool 10 and bridge plug 13 are lowered as a unit into the well casing 11 on the wire line 12, and when the desired depth is reached, the power charge 16 is ignited electrically to cause the actuator to expand the bridge plug 13 into contact with the casing 11 and to break the frangible connection 14, as shown in FIG- URE 2c. The actuator or setting tool assembly 10 may then be withdrawn from the well casing on the wire line 12, leaving the bridge plug 13 in place in the casing.

The actuator or setting tool 10 includes a cylinder member 20 provided with an axial cylindrical bore 21. A piston 22 having seal rings 23 is slidably mounted within the bore 21. A downward-extending piston rod 25 is fixed to the piston and extends through the central axial opening 26 in the lower end wall 27 of the cylinder member 20. Seal rings 28 mounted in the opening 26 engage the piston rod 25.

A post 30 is fixed to the piston 22 and extends axially upward therefrom and projects slidably through an opening 32 in the annular plug 33. Seal rings 34 in the opening 32 contact the post 30. The annular plug 33 is formed on the lower end of the axial concentric sleeve 35, which is provided on the lower end of the body 37. Threads 38 connect the upper end of the cylinder member 20 to the body 37. Seal rings 39 on the body engage the cylinder member 20 to prevent leakage. A seal ring 40 on the annular plug also engages the cylinder member 20 to prevent leakage. The annular plug 33 forms the upper end wall of a chamber 42 within the cylindrical bore 21 of the cylinder member 20. The end wall 27 forms the lower end wall of the chamber 42.

An axial-extending central tube 45 is fixed to the upper end of the post 30 and extends through the space 46 within the sleeve 35 and between the annular plug 33 and the wall 47 of the body 37. A central opening 48 in the wall 47 slidably receives the tube 45, and seal rings 49 in the opening 48 engage the outer surface of the tube 45. The walls of the body 37 define a closed pocket 51 adapted to receive high-pressure gas from ignition of the powder charge 16. The ignition system for the powder charge 16 is conventional and is operated by electrical energy transmitted through an electric lead wire 52 in the cable 12.

When the powder charge 16 is ignited, gas under high pressure in the pocket 51 passes through the central opening 53 in the tube 45 and through the connecting central passage 54 in the post 30 and outward through lateral ports 55 in the piston 23. The high-pressure gas is thus delivered into the chamber 42 below the piston 22. The piston 22 moves upward, causing the body of oil 57 in the chamber 42 above the piston to pass through one or more restricted ports 58 in the annular plug 33 into the closed cavity 59, defined between the sleeve 35 and the cylinder member 20. This cavity 59 is initially filled with air. It may be at atmospheric pressure, or somewhat higher in order to return the piston 22 to its initial position. Upward movement of the piston 22 under the force of high-pressure gas is slowed by the dashpot action of the oil 57 passing through the restriction 58.

The lower end of the piston rod 25 is connected by coupling 60 to the frangible pin 14 having a weakened section 61. The bridge plug assembly 13 has a mandrel 62 connected to the lower end of the frangible pin 14. The usual expansible elastomeric sleeve 63 is mounted on the mandrel 13 and is caused to expand outward into engagement with the casing 11 when the mandrel 62 moves upward with respect to the ring 64. The usual cones 65 are provided at the opposite ends of the expansible sleeve 63, and wedge slips 66 co-operate with the cones 65 to hold the sleeve 63 in expanded position, as shown in FIGURE 20. The slips 66 may be initially retained in place by frangible bands 67 or by other conventional means. The ring 64 is engaged by the lower end of the spacer 15 which is connected by threads 68 to the lower end of the cylinder member 20.

Accordingly, when the piston 22 moves upward in the chamber 42 the spacer 15 acts in compression while the piston rod 25 acts in tension. After the bridge plug 13 has been set, continued upward movement of the piston 22 overloads the frangible pin 14 in tension, causing it to rupture. Recoil of the actuator 10 at the moment of rupture of the frangible pin 14 is minimized because of the dashpot action of the oil being transferred from the upper portion of the chamber 42 through the restricted ports 58 into the closed cavity 59. The chamber 42 below the piston 22 as well as the pocket 51 remained filled with gas under pressure, after the piston 22 has moved to the upper end of its stroke.

The upper end of the space 46 is vented through ports 70 and 71 to the space outside the actuator tool 10 and within the casing 11. Accordingly, any hydrostatic head of liquid in the casing acts through the ports 71 and 70 and through the space 46 on the exposed upper end of the post 30. Also, the piston rod 25 below the seal rings 28 is exposed to the same hydrostatic pressure through the ports 72 in the upper end of the spacer 15. The relative diameters of the post 30, tube 45, and piston rod 25 are so chosen that the effective area of the piston rod 25 is equal to the effective area of the post 30, minus the efi'ective area of the tube 45. The result is that the piston is hydrostatically balanced regardless of the depth of submergence of the actuator in liquid within the well casing 11.

Having fully described my invention, it is to be understood that I am not to be limited to the details herein set forth, but that my invention is of the full scope of the appended claims.

I claim:

1. An acuator device for a well tool, comprising in combination: a cylinder member having a bore and having upper and lower end walls defining a chamber within said bore, each end wall having an axial opening, a piston slidably mounted within said bore, a piston rod fixed to the piston and projecting slidably through the opening in the lower end wall, a post fixed to the piston and projecting slidably through the opening in the upper end wall, an axial sleeve fixed to the upper end wall forming a closed cavity within the cylinder member, ports in the end wall connecting said cavity to said chamber, the sleeve having interior space into which said post may project, port means venting said interior space to the exterior of said actuator device, walls forming a pocket above the sleeve to receive a pressure-generating charge, and means forming a passage connecting said pocket to the chamber below the piston.

2. An actuator device for a well tool, comprising in combination: a cylinder member having a bore and having upper and lower end walls defining a chamber within said bore, each end wall having an axial opening, a piston slidably mounted within said bore, the chamber above the piston containing oil, a piston rod fixed to the piston and projecting slidably through the opening in the lower end Wall, a post fixed to the piston and projecting slidably through the opening in the upper end wall, an axial sleeve fixed to the upper end wall forming a closed cavity within the cylinder member, said closed cavity containing atmospheric air, ports in the end wall connecting said cavity to said chamber, the sleeve having interior space into which said post may project, port means venting said interior space to the exterior of said actuator device, walls forming a pocket above the sleeve to receive a pressure-generating charge, axially slidable telescoping parts including a tube extending between said post and said pocket, and passage means in the post and piston connecting the chamber below the piston to said pocket through the interior of the tube.

3. An actuator device for a well tool, comprising in combination: a cylinder member having a bore and having upper and lower end walls defining a chamber within said bore, each end wall having an axial opening, a piston slidably mounted within said bore, a piston rod fixed to the piston and projecting slidably through the opening in the lower end wall, a post fixed to the piston and projecting slidably through the opening in the upper end wall, an axial sleeve fixed to the upper end wall forming a closed cavity Within the cylinder member, ports in the end wall connecting said cavity to said chamber, the sleeve having interior space into which said post may project, port means venting said interior space to the exterior of said actuator device for balancing said piston against hydrostatic pressure of fluid in which the actuator device may be immersed, Walls forming a pocket above the sleeve to receive a pressure-generating charge, axially slidable telescoping parts including a tube extending between said post and said pocket, and passage means in the post and piston connecting the chamber below the piston to said pocket through the interior of the tube.

4. An actuator device for a well tool, comprising in combination: a cylinder member having a bore and having upper and lower end walls defining a chamber within said bore, each end wall having an axial opening, a piston slidably mounted within said bore, a piston rod fixed to the piston and projecting slidably through the opening in the lower end wall, a post fixed to the piston and projecting slidably through the opening in the upper end wall, an axial sleeve fixed to the upper end wall forming a closed cavity within the cylinder member, ports in the end wall connecting said cavity to said chamber, the sleeve having interior space into which said post may project, port means venting said interior space to the exterior of said actuator device for balancing said piston against hydrostatic pressure of fluid in which the actuator device may be immersed, walls forming a pocket above the sleeve to receive a pressure-generating charge, one of the walls having an opening, a tube fixed coaxially to said post and slidably received in the latter said opening, and passage means in the post and piston connecting the chamber below the piston to said pocket through the interior of the tube.

5. An actuator device for a well tool, comprising in combination: a cylinder member having an axial bore, a piston slidable axially within said bore and having a piston rod fixed thereto and projecting downward therefrom, the cylinder member having an end wall provided with an opening slidably receiving said piston rod, the piston also having a concentric cylindrical post fixed thereto and projecting upward therefrom, a tubular body fixed to the cylinder member and having an axial sleeve extending into said cylinder member and having an annular plug sealed within the cylinder member above said piston, said annular plug having an opening slidably receiving said post, the space within the cylindrical bore between the end wall and the annular plug comprising a chamber, said sleeve and said cylinder member co-operating to form a closed cavity, ports in said annular plu-g connecting said closed cavity to the chamber above said piston, ports in the body member venting the space within the sleeve to the exterior of the actuator device, the body having walls forming a pocket above the sleeve to receive a pressuregenerating charge, axially slidable telescoping parts including an element extending between said post and said pocket, and passage means connecting the chamber below the piston to said pocket.

6. An actuator device for a well too], comprising in combination: a cylinder member having an axial bore, a piston slidable axially Within said bore and having a piston rod fixed thereto and projecting downward therefrom, the cylinder member having an end wall provided with an opening slidably receiving said piston rod, the piston also having a concentric cylindrical post fixed thereto and projecting upward therefrom, a tubular body fixed to the cylinder member and having an axial sleeve extending into said cylinder member and having an annular plug sealed within the cylinder member above said piston, said annular plug having an opening slidably receiving said post, the space within the cylindrical bore between the end wall and the annular plug comprising a chamber, said sleeve and said cylinder member co-operating to form a closed cavity, ports in said annular plug connecting said closed cavity to the chamber above said piston, ports venting the space within the sleeve to the exterior of the actuator device for balancing said piston against hydrostatic pressure of fluid in which the actuator device may be immersed, the body having walls forming a pocket above the sleeve to receive a pressure-generating charge, axially slidable telescoping parts including a tube extending between said post and said pocket, and passage means in the post and piston connecting the chamber below the piston to the pocket through the interior of the tube.

7. For use with a well tool having two parts adapted for relative axial movement, an actuator device comprising, in combination: a cylinder member having an axial bore, means for connecting the cylinder member to one of the well tool parts, a piston slidable axially within said bore of said cylinder member and having a piston rod fixed thereto and projecting downward therefrom, means for connecting said piston rod to the other of the well tool parts, the cylinder member having an end wall provided with an opening slidably receiving said piston rod, the piston also having a concentric cylindrical post fixed thereto and projecting upward therefrom, a tubular body fixed to the cylinder member and having an axial sleeve extending into said cylinder member and having an annular plug sealed within the cylinder member above said piston, said plug having an opening slidably receiving said post, the space within the cylindrical bore between the end wall and the annular plug comprising a chamber, said sleeve and said cylinder member cooperating to form a closed cavity, ports in said annular plug connecting said closed cavity to the chamber above said piston, ports in the body member venting the space within the sleeve to the exterior of the actuator device, the body having a pocket above the sleeve to receive a pressure-generating charge, axially slidable telescoping parts including a tube extending between said post and said pocket, and passage means in the post and piston connecting the chamber below the piston to the pocket through the interior of the tube.

8. The device of claim 7 in which the closed cavity contains atmospheric air and the chamber above the piston contains oil.

9. For use with a well tool having two parts adapted for relative axial movement, an actuator device comprising, in combination: a cylinder member having an axial bore, means for connecting the cylinder member to one of the well tool parts, a piston slidable axially within said bore of said cylinder member and having a piston rod fixed thereto and projecting downward therefrom, means for connecting said piston rod to the other of the well tool parts, the cylinder member having an end wall provided with an opening slidably receiving said piston rod, the piston also having a concentric cylindrical post fixed thereto and projecting upward therefrom, a tubular body fixed to the cylinder member and having an axial sleeve extending into said cylinder member and having an annular plu-g sealed within the cylinder member above said piston, said annular plug having an opening slidably receiving said post, the space within the cylindrical bore between the end wall and the annular plug comprising a chamber, said sleeve and said cylinder member co-operating to form a closed cavity, ports in said annular plug connecting said closed cavity to the chamber above said piston, ports in the bodv member venting the space within the sleeve to the exterior of the actuator device, the body having walls forming a pocket above the sleeve to receive a pressure-generating charge, one of the walls having an opening, a tube fixed on said post and slidably received in the latter said opening, and passage means in the post and piston connecting the chamber below the piston to the pocket through the interior of the tube.

References Cited by the Examiner UNITED STATES PATENTS 2,978,028 4/1961 Webb 16663 3,125,162 3/1964 Briggs et al l66-123 3,138,207 6/1964 Peppers 166-63 3,186,485 6/1965 Owen 166-63 3,220,480 11/1965 Myers -a 166-63 CHARLES E. OCONNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner. 

1. AN ACTUATOR DEVICE FOR WELL TOOL, COMPRISING IN COMBINATION: A CYLINDER MEMBER HAVING A BORE AND HAVING UPPER AND LOWER END WALLS DEFINING A CHAMBER WITHIN SAID BORE, EACH END WALL HAVING AN AXIAL OPENING, A PISTON SLIDABLY MOUNTED WITHIN SAID BORE, A PISTON ROD FIXED TO THE PISTON AND PROJECTING SLIDABLY THROUGH THE OPENING IN THE LOWER END WALL, A POST FIXED TO THE PISTON AND PROJECTING SLIDABLY THROUGH THE OPENING IN THE UPPER END WALL, AN AXIAL SLEEVE FIXED TO THE UPPER END WALL FORMING A CLOSED CAVITY WITHIN THE CYLINDER MEMBER, PORTS IN THE END WALL CONNECTING SAID CAVITY TO SAID CHAMBER, THE SLEEVE HAVING INTERIOR SPACE INTO WHICH SAID POST MAY PROJECT, PORT MEANS VENTING SAID INTERIOR SPACE TO THE 